Codeigniter unicode问题

I'm a seasoned PHP developer, but fairly new to using Codeigniter. I'm having a very strang challenge I've never encountered before. I've created an "assets" folder to put my css, js and images in. Within the js folder, I've created a "main.js". Initiallly this file saved and loaded in the page just fine. However, after making changes to the file, it now keeps the initial state of the file (gives appearance of caching), but adds unicode chatacters to the bottom of the file. I view the file itself on the server (vi), and the changes are there (no unicode). But when I load this file in the browser, directly or from the template (link src=""), it loads the initial state with unicode characters at the bottom. See screen shot. I am at a loss. If I revert the file to it's initial state, the page loads without the unicode characters. Can someone please help?